For many reasons, there has been a growth in the development of technologies used to harness alternative renewable sources of energy. One such renewable source of energy that has seen some attention is solar energy.
Conventional relatively large solar panel assemblies having photovoltaic cells have been known in the art for some time. However, such assemblies have conventionally not been able to economically harness energy from the sun, typically because photovoltaic cells are currently too expensive.
Consequently, there has been an interest in concentrated photovoltaics. The theory behind concentrated photovoltaics is to use optical elements to concentrate sunlight received over a relatively larger area into a relatively smaller area at which a photovoltaic cell (or some other means of harvesting solar energy) is located. The combination of the concentrating optical elements and the smaller photovoltaic cell would, in theory, at the current time, be less expensive than would be an equivalent larger photovoltaic cell required capture the same amount of sunlight. The first generations of concentrating optical elements were, however, quite complex and bulky, and suffered from many other drawbacks known in the art. Thus concentrated photovoltaic solar energy concentrators have not seen widespread general commercial acceptance.
A drive to reduce the complexity and bulkiness of conventional optics led to the development of planar solar energy concentrators. Planar solar energy concentrators are generally planar relatively compact optical structures that typically employ a variety of optical elements (commonly as part of an array) to deflect and concentrate sunlight and guide it within the structure to a location where it can be harvested.
There are many possible configurations of planar solar energy concentrators. Some examples of various planar solar energy concentrators are shown in U.S. Patent Applications Publication Nos. US 2008/0271776 A1 (Morgan); US 2006/0269213 A1 (Hwang et al.); US 2008/0048102 A1 (Kurtz et al.); and US 2011/0096426 A1 (Ghosh et al.); the entirety of each of those applications is incorporated herein by reference.
Conventionally such concentrators may be divided into a layer that deflects and/or concentrates light (in the present application called a light insertion layer—but also called by a variety of other names in the art), and into a layer that traps and guides light (in the present application called a light guide layer—but also called by a variety of other names in the art) to a location(s) for harvesting. Depending on the configuration and construction of a particular concentrator, these layers may be areas of a unitarily manufactured structure or may be separate physical structures that have been separately manufactured and subsequently brought together to form a single structure that operates as a unit.
Current conventional planar solar energy concentrators are not easy to manufacture however. In some constructions where there are two layers that are separately fabricated and are subsequently brought together, extreme precision, both in the fabrication of the layers and in their alignment when they are being brought together to form a unit, is very important. Small defects either in fabrication or in alignment will have a very significant negative effect on the percentage of light impinging on the concentrator that the concentrator is able to make available for harvesting, and must generally be avoided.
For example, a portion of a prior art planar solar energy concentrator 010 is shown in FIG. 1. This example is taken from that shown in FIG. 24A of U.S. Pat. No. 7,873,257, herein incorporated by reference in its entirety. Concentrator 010 includes a light insertion layer 012 and a light guide layer 014. The light insertion layer 012 has been made of injection-molded poly(methyl) methacrylate (commonly known in the art as “PMMA”), a light-transmissive material. The light insertion layer 012 has a planar optical entry surface 016, an array of optical redirecting elements 018, and an array of optical exits 020. Each of the optical redirecting elements 018 redirects and concentrates light 022 it receives through the optical entry surface 016 towards an associated one of the optical exits 020 via total internal reflection (TIR). (TIR occurs because there is an air gap 028 between the light insertion layer 012 and the light guide layer 014.) In particular, each of the optical redirecting elements 018 is a parabolic section in cross-section, such that parallel light rays 022 reflecting off the optical redirecting elements 018 are focused towards a focal point (unlabeled). However, before the reflected focused light rays 024 reach the focal point, they pass through the optical exits 020. The optical exits 020 also redirect light that they receive, albeit via refraction, and thus they shift the focal point of the reflected light 024 as is shown in the figure. (The path that the light would have taken were it not for the refraction occurring at the optical exits 020 is shown in FIG. 1 by the dotted lines 026. The path that the light actually takes because of the refraction is shown in FIG. 1 by the solid lines 027.) The refraction also occurs because of the air gap 028 between the light insertion layer 012 and the light guide layer 014.
The light guide layer 014 has also been made of injection-molded PMMA. The light guide layer 014 has a first surface 030 and a second surface (not shown). The first surface 030 of the light guide layer 014 has a series of projections 032 having the same spacing therebetween as the optical redirecting elements 018 of the light insertion layer 012. There is a one-to-one relationship between the optical exits 020 of the light insertion layer 012 and the projections 032 of the first surface 030 of the light guide layer 014. Each of the projections 032 has a planar portion 034 that is parallel to the optical exit 020 of the light insertion layer 012 with which it is associated.
The light insertion layer 012 and the light guide layer 014 are structured and arranged one with respect to the other such that light 027 passing through the air gap 028 between them enters the light guide layer 014 through the planar portions 034 of the projections 032 thereof. As the light 027 enters the projection 032, the light 027 is again deflected via refraction such that the focal point of the light 036 once inside the projection 032 of the light guide layer 034 is shifted again, this time to the focal point 038 shown in FIG. 1. The light insertion layer 012 and the light guide layer 014 are structured and arranged one with respect to the other such that after the final refraction referred to above, the focal point 038 of the light entering the main body 040 of the light guide layer 014 is immediately below the projection 032 such that all of the light 036 having entered the projection 032 will pass through the focal point 038 and continue on within the main body 040 of the light guide layer 014 (shown as light rays 042) and will be guided through a series of multiple total internal reflections (not shown) in between the first surface 030 and the second surface (not shown) of the light guide layer 014 to the optical output (not shown) of the light guide layer 014 for harvesting.
As is evident to those skilled in the art, a very high degree of precision is required in fabricating the solar concentrator 010 shown in FIG. 1 in order for as much of the light entering solar concentrator 010 as possible to be conducted to the optical output of the light guide layer 014 for harvesting. A slight misfabrication of either of the light insertion layer 012 or of the light guide layer 014 or a slight misalignment between them will shift the path of the light entering the solar concentrator 010 such that much less, or in some cases none, of the light will be available for harvesting. At the time of filing of the present application, such a decrease in the light available for harvesting would render the solar concentrator 010 uneconomical.
ProjetCadreFR
It is thus an object of the present invention to ameliorate at least some of the inconveniences present in the prior art and to provide an improved solar concentrator as compared with at least some of the prior art.
In one aspect, there is provided a solar concentrator comprising a substantially planar light insertion layer. The light insertion layer is made of light-transmissive material and includes an optical entry surface for receiving light. The light insertion layer also includes an array of optical redirecting elements. Each of the optical redirecting elements is in optical communication with the optical entry surface of the light insertion layer. The light insertion layer also includes an array of optical exits. Each of the optical exits is in optical communication with an associated one of the optical redirecting elements. Each of the optical redirecting elements is for receiving light and redirecting received light towards the optical exit associated with that one of the optical redirecting elements. The solar concentrator also comprises a substantially planar light guide layer. The light guide layer is made of light-transmissive material and includes a first surface for receiving light exiting the light insertion layer through the optical exits. The light guide layer also includes a second surface opposite the first surface. The first surface and the second surface of the light guide layer are structured and arranged with one respect to the other such that light entering the light guide layer is guided through the light guide layer to at one least one light guide layer optical output surface via a series of reflections. The solar concentrator also comprises an array of optical apertures optically interconnecting the light insertion layer and the light guide layer formed by interfaces between at least one of the light insertion layer and the light guide layer and at least one deformed optical coupling element.
As was discussed hereinabove, in at least some conventional two-layer planar solar energy concentrators, a very high degree of precision is required in the fabrication and alignment of the layers. Some embodiments of the present invention attempt to have nearly the same efficiency (and other attempt to improve the efficiency) of transmission of the light through the solar concentrator as compared with conventional planar solar collectors, without requiring the same degree of precision and accuracy in the fabrication thereof to achieve this. In simple terms, this is accomplished by designing the layers such that optical apertures optically interconnecting the layers are formed via at least one deformable optical coupling element being deformed at the time that two layers are brought into contact with one another during the fabrication of the solar concentrator, thereby directly optically coupling the two layers. The deformable optical coupling element(s) allows for the aforementioned precision and accuracy to be reduced (as compared with at least some of the prior art) by allowing for some “play” between the layers that has little or no effect on the optical communication between them. Thus, in some embodiments the high percentage of light recovery found in some conventional planar solar energy concentrators can be maintained.
In the present specification, unless the context clearly requires otherwise, the term “planar” is not intended in the geometric sense of the word (i.e. it is not intended to mean a two-dimensional structure being formed by two intersecting lines, having zero curvature). Rather, as would be understood be those skilled in the art of planar solar energy concentrators, “planar” in this specification generally simply means a structure having a depth that is relatively insubstantial in comparison to its length or width, when the structure is viewed from above. Thus “planar” structures in the context of the present specification may include structures that are wedge-shaped, stepped, or slightly curved, as well as structures that have relatively small projections and/or indentations, and structures having any combination of the foregoing.
Light Insertion Layer
The light insertion layer is a layer of a planar solar energy concentrator having light-transmissive material(s) that is physically and optically structured to cause light to be inserted via redirection (i.e. causing the light to change its direction of travel) and/or concentration (i.e. causing an increase in the irradiance of the light) into the light guide layer. In the context of the present specification, a material is light-transmissive if light can travel through the material without any material losses caused by absorption or scattering due to the material itself. Non-limiting examples of light-transmissive materials include glasses, PMMA, silicones, Cyclo-Olefin Polymers (COP), Cyclo-Olefin Copolymers (COC), epoxy-based materials, urethane materials, other co-polymer materials, other polymeric materials, and combinations thereof.
The light insertion layer has an optical entry surface for receiving light to be inserted by the light insertion layer into the light guide layer. No particular structure of the optical entry surface is required in the present context. Any structure capable of accomplishing the necessary function will suffice. Some specific configurations of light insertion layers are detailed hereinbelow. The optical entry surface of the light insertion layer may be the optical entry surface of the solar energy concentrator itself, but it need not be. The optical entry surface of the light insertion layer may be of the same material as other portions or the remainder of the light insertion layer (as the case may be) or it may be a different material.
The light insertion layer includes an array of optical redirecting elements. In the present context, an optical redirecting element is a structure (or combination of structures functioning together) that causes light to deviate from the course of travel that the light would have had prior to having encountered the optical redirecting element. Typically, optical redirecting elements function by refraction, reflection, or a combination thereof. Thus, non-limiting examples of optical redirecting elements include boundary surfaces between media having different refractive indices (such that total internal reflection at the surface will occur), surfaces having been coated with a reflective material (such as a metal), lenses, Fresnel lenses, Winston cones, prisms and combinations thereof. The boundary or otherwise reflective surfaces of optical redirecting elements can be analytic or non-analytic surfaces.
Each of the optical redirecting elements is in optical communication with the optical entry surface of the light insertion layer. Two structures are in “optical communication” in the context of the present specification (when the solar energy concentrator is correctly in use) when light may travel from one structure to the other, either directly or indirectly (including via other structures). Thus, light entering the light insertion layer through the optical entry surface thereof will (immediately or eventually) be incident on one of elements of the array of optical redirecting elements.
In some embodiments, the optical entry surface of the light insertion layer includes at least some of the optical redirecting elements. In some of such embodiments it may include all of the optical redirecting elements. In some embodiments, the optical redirecting elements are compound optical elements (as opposed to singular optical elements). In some of such embodiments each of the compound optical elements includes a portion of the optical entry surface and a portion physically spaced apart from the portion of the optical entry surface. Thus, in some embodiments the optical redirecting elements of the optical entry surface are optical concentrating elements, lenses in a non-limiting example.
In some embodiments, the optical redirecting elements are optical reflecting elements. In some of such embodiments, the optical redirecting elements redirect the received light via total internal reflection; in others they redirect the received light via a coated reflective surface (sometimes referred to in the art as a mirror coated surface). Non-limiting examples include surfaces coated with a metal such as aluminum or silver, or a dielectric.
In some embodiments, the optical redirecting elements are optical concentrating elements, lenses or shaped reflective surfaces in non-limiting examples. In some of such embodiments, the optical redirecting elements are optical focusing elements, parabolic reflective surfaces in non-limiting examples.
In some of such embodiments, each of the optical redirecting elements includes at least one parabolic section in cross-section, such that each of the optical redirecting elements is able to focus light it receives. In some of such embodiments, each of the optical redirecting elements has a focal point located at least in the vicinity of (i.e. at or in the vicinity of) the optical aperture associated with that optical redirecting element. (In the context of the present specification an “optical aperture” is a physical interconnection at a contact interface between two structures that allows light to exit one of the structures and enter the other—this is described in further detail below.)
In some embodiments, at least a majority of the optical redirecting elements of the light insertion layer are annular (when viewed from above—as opposed to in cross-section) and of a sequentially decreasing diameter. This configuration is beneficial for causing the light to be inserted into the light guide layer in such a way that (depending on the structure of the light guide layer) the light having been redirected by the light insertion layer may be guided in the light guide layer to a common area for harvesting.
The light insertion layer also includes an array of optical exits. An optical exit is a structure through which light may be output from the light insertion layer when the solar energy concentrator is correctly in use. Each of the optical exits is in optical communication with an associated one of the optical redirecting elements such that light received by a redirecting element is redirected by the element (optically) towards an optical exit associated with that element. There may be a one-to-one relationship between the optical redirecting elements and the optical exits of the light insertion layer, but that is not necessarily the case.
Light Guide Layer
The light guide layer is a substantially planar layer having light-transmissive layer material(s) that is physically and optically structured to cause light entering the layer from the light insertion layer through various optical apertures to be guided to a common location for harvesting. The light guide layer has a first surface for receiving light exiting the light insertion layer through the optical exits of that layer. (Thus the array of optical apertures—discussed in further detail below—is, in most cases, at the physical interface between the optical exits of the light insertion layer and the first surface of the light guide layer—but that is not necessarily the case). The light guide layer also includes a second surface opposite the first surface. The first surface and the second surface are structured and arranged one with respect to the other such that light entering the light guide layer (through optical apertures) is guided through the light guide layer to at least one light guide layer optical output surface via a series of reflections. The reflections may be caused by any structure sufficient to cause the same that does not materially obstruct the entry of light from the light insertion layer through the optical apertures into the light guide layer. Non-limiting examples of structures capable of causing such reflections are the first and the second surfaces being boundary surfaces between media having different refractive indices (such that total internal reflection at the surfaces will occur) and/or the first and the second surfaces having been (at least partially) coated with a reflective material (such as a metal or a dielectric). As was the case with the light insertion layer, the light guide layer may be made of a number of suitable materials or combinations thereof, such as glass and polymers such as PMMA, silicone, COP and COC.
In some embodiments, the first surface of the light guide is generally flat. In other embodiments, the first surface of the light guide layer includes a series of projections at which at least a part of the optical apertures is formed. In still other embodiments, the first surface of the light guide layer includes a series of indentations at which at least a part of the optical apertures is formed.
In some embodiments, the light guide layer is wedge-shaped. In other embodiments, the light guide layer is flat. In still other embodiments, the light guide layer is shaped other than flat or wedge-shaped, such as trumpet-shaped, for example.
In some embodiments, at least one of the first and the second surfaces of the light guide layer is stepped.
In some embodiments, the first surface and the second surface are structured and arranged one with respect to the other such that light entering the light guide layer is guided through the light guide layer to the at least one light guide layer optical output surface via total internal reflection.
Deformed Optical Coupling Element
As was noted above, an array of optical apertures optically interconnecting the light insertion layer and the light guide layer is formed by at least one deformed optical coupling element. In the present context, an “optical coupling element” is a solid, optically transmissive structure that is in physical contact with another optically transmissive structure (e.g. by direct contact). Pressure at the contact interface between the optical coupling element and the other optically transmissive structure forms the optical aperture(s), allowing light in one structure to pass through the interface into the other structure without any material obstruction to the light's path. The efficiency of light transfer may therefore be maintained or improved as compared to conventional planar solar energy concentrators.
The deformed optical coupling elements may be separate structures from other structures of the planar solar concentrator (e.g. the light insertion layer, the light guide layer), or they may be portions of other structures of the planar solar concentrator (e.g. the light insertion layer, the light guide layer) or some combination thereof. Thus, in some embodiments, the at least one deformed optical coupling element is disposed in between the light insertion layer and the light guide layer and optically couples each of the optical exits of the light insertion layer to the first surface of the light guide layer. In some other embodiments, the at least one deformed optical coupling element is at least a portion of each of the optical exits of the light insertion layer. In still some embodiments, the at least one optical coupling element is at least a portion of the first surface of the light guide layer.
Thus, in some embodiments, the at least one optical coupling element is chemically and/or mechanically bonded (and thereby optically coupled) to (at least) one of the light insertion layer or the light guide layer, for example, via an overmolding process. “Overmolding” in the context of the present specification is a process by which a second material (for example, a thermoplastic elastomer) is molded (e.g. typically injection molded) onto a first material (for example, rigid plastic or glass, which may, for example, have been injection molded or otherwise formed) in such a way that the second material is mechanically and/or chemically bonded to the first material. Where the optical coupling element is overmolded or otherwise bonded to one of the light insertion layer or the light guide layer, for most purposes of the present specification the optical coupling element becomes part of that layer. Thus, during fabrication of the planar solar concentrator, an optical aperture(s) will be formed at the contact interface (where the optical coupling element becomes deformed) between the one of the light insertion layer and the light guide layer having the optical coupling element(s) bonded thereto and the other of the light insertion layer and the light guide layer, directly optically coupling the layers such that light does not have to travel through an air gap between them, for example, to exit one of the layers and enter the other.
In other embodiments, the at least one optical coupling element is disposed between the light insertion layer and the light guide layer, but neither chemically nor mechanically bonded to either one of the layers. In such embodiments, the array of optical apertures is a multi-dimensional array of optical apertures including at least a first sub-array of interfaces (i.e. areas of contact) between the light insertion layer and the deformed optical coupling element through which light exits the light insertion layer, and a second sub-array of interfaces between the deformed optical coupling element and the light guide layer through which light enters the light guide layer. (In the context of the present specification, for ease of reference, the first sub-array of optical apertures may, at times, be termed “light insertion layer exit optical apertures” and the second sub-array of optical apertures may, at times, be termed “light guide layer entry optical apertures”.) In this manner, via the intermediary of the at least one deformed optical coupling element, the light insertion layer may be optically coupled to the light guide layer, allowing light to travel between them without passing through an air gap. (In other embodiments, for example such as those in which there are multiple optically active structures optically between the light insertion layer and the light guide layer, there may be additional sub-arrays of optical apertures.)
In context of the present specification, the expression “at least one deformed optical coupling element” is meant to include both embodiments where there is a single physical optical coupling structure directly coupling the light insertion layer to the light guide layer and forming the array of optical apertures, and embodiments where there are multiple physical optical coupling structures directly coupling the two layers (be they compound structures or multiple discrete structures) and forming the array of optical apertures (whether on a one-to-one basis or otherwise). Thus, in some embodiments the at least one deformed optical coupling element is a single optical coupling element forming the array of optical apertures optically interconnecting the light insertion layer and the light guide layer. In some other embodiments, the at least one deformed optical coupling element is a plurality of optical coupling elements, each one of the plurality of optical coupling elements forming at least one of the optical apertures of the array of optical apertures optically interconnecting the light insertion layer and the light guide layer.
An optical coupling element is “deformed” (or “deformable”) in the present context, when during the manufacture of the planar solar concentrator, typically as a result of physically bringing the light insertion layer into contact with the light guide layer, the shape of the optical coupling element changes (or is changeable in the case of deformable). This change in shape allows the optical coupling element to better conform to the structures of the concentrator with which it will be in physical contact. Non-limiting examples of materials that are deformable in the present context are silicone having a hardness in the range of 20-60 on the Shore OO scale or 1-14 on the Shore O scale, and injection molded Evonik™ 8N having a hardness in the range of 1-35 on the Brinell scale or 75-100 on the Rockwell M scale).
In some embodiments, the deformed optical coupling element is elastic (i.e. it will recover its original shape if the solar concentrator is (at least partially) disassembled, e.g. the light insertion layer and the light guide layer being removed from one another.) In other embodiments, the deformed optical coupling element is non-elastic. In some embodiments where the deformed optical coupling element is elastic, it is elastomeric. In some of such embodiments the deformed optical coupling element is silicone.
As was noted above, in some embodiments, each of the optical redirecting elements of the light insertion layer has a focal point located at or in the vicinity of the optical aperture associated with that optical redirecting element. (e.g. the focal point is located within the optical coupling element or adjacent it within either the light insertion layer or the light guide layer). In this manner, light entering the light insertion layer will be redirected by the optical redirecting elements so as to pass through the apertures directly into the light guide layer (e.g. reducing loss due to, for example, back scattering effects when light enters the light insertion layer). Since the aperture is only created at the time the optical coupling element is deformed when, for example, the light insertion layer and the light guide layer are brought together, this allows for the aforementioned “play” between them which reduces the precision and accuracy with which they must be manufactured and/or aligned.
The redirecting elements and the deformable elements of some embodiments are structured and arranged one with respect to the other in such a way that in most (if not in all) the ways in which the deformable element will be deformed during solar concentrator assembly, the focal point of the redirecting element will be located with respect to the aperture so as to maximize the light going through the aperture. (For example, the focal point may be at the aperture or immaterially spaced apart from it.) This is in contrast to prior art designs which did not incorporate any similar flexibility in the design, i.e. they were designed such that the focal points of the redirecting surfaces had to be situated in a particular location when the final device was assembled or else the light passing from the light insertion layer to the light guide layer would not have been maximized, or would have not entered the light guide layer at all. Hence, the required precision and accuracy required in terms of manufacturing and assembly of the prior art planar solar concentrators referred to above. In these prior art designs there was no play between the layers thereof. If the layers were mismanufactured or misassembled, then some, if not all, of the light entering the light insertion layer would be lost and could not be harvested.
Other Optional Features
In some embodiments, the solar concentrator further comprises at least one secondary optical element in optical communication with the at least one optical output surface of the light guide layer and with the at least one solar energy collector. This may be the case, for example, in some embodiments, where, depending on the construction of, for example, the light guide layer and the amount of light travelling through it, a significant amount of heat is generated. Depending on the material(s) of construction of the light guide layer, this amount of heat can cause damage to the light guide layer. Thus, a secondary optical element, made of a more heat-resistant material (e.g. typically a glass) may be present to guide the light from the light guide layer output surface(s) to an area where it may be harvested. Secondary optical elements have other uses as well in planar solar concentrators.
In some embodiments, the solar concentrator further comprises at least one deformable optical coupling element coupling the at least one optical output surface of the light guide layer to an input surface of the at least one secondary optical element. Such a structure may, for example, provide increased tolerances in the manufacturing process and/or improve the transfer efficiency of light from the light guide layer to the at least one secondary optic.
In some embodiments, the solar concentrator further comprises at least one solar energy collector in optical communication with the at least one optical output surface of the light guide layer, for receiving light having been guided through the light guide layer. (Such communication may be direct or may be via a tertiary optical element, for example.) In some of such embodiments, the solar energy collector is a photovoltaic cell.
Method of Fabricating a Planar Solar Energy Concentrator
In a further aspect, there is provided a method of fabricating a solar energy concentrator. The method comprises: (1) Positioning at least one deformable optical coupling element in between: (i) A substantially planar solar concentrator light insertion layer. The light insertion layer has light-transmissive material and has an array of optical redirecting elements, and an array of optical exits. Each of the optical exits is in optical communication with an associated one of the optical redirecting elements. Each of the optical redirecting elements is for receiving light and redirecting received light towards the optical exit associated with that one of the optical redirecting elements. (ii) And a substantially planar solar concentrator light guide layer. The light guide layer has light-transmissive material, a first surface for receiving light exiting the light insertion layer through the optical exits, and a second surface opposite the first surface. The first surface and the second surface are structured and arranged one with respect to the other such that light entering the light guide layer is guided through the light guide layer to at least one light guide layer optical output surface via a series of reflections. The deformable optical coupling element is positioned such that, when deformed, the at least one deformable optical coupling element optically couples each of the optical exits of the light insertion layer to the first surface of the light guide layer forming an array of optical apertures optically interconnecting the light insertion layer and the light guide layer. (2) And, deforming the at least one deformable optical coupling element thereby forming the array of optical apertures optically interconnecting the light insertion layer and the light guide layer.
In an additional aspect, there is provided a method of fabricating a solar concentrator. The method comprising: (1) Positioning (i) a substantially planar solar concentrator light insertion layer. The light insertion layer having light-transmissive material, an array of optical redirecting elements, and an array of optical exits. Each of the optical exits is in optical communication with an associated one of the optical redirecting elements. Each of the optical redirecting elements is for receiving light and redirecting received light via reflection towards the optical exit associated with that one of the optical redirecting elements. (ii) And, substantially planar solar concentrator light guide layer. The light guide layer having light-transmissive material, a first surface for receiving light exiting the light insertion layer through the optical exits, and a second surface opposite the first surface. The first surface and the second surface are structured and arranged one with respect to the other such that light entering the light guide layer is guided through the light guide layer to at least one light guide layer optical output surface via a series of reflections. At least a portion of the optical exits of the light insertion layer is capable of deformingly optically coupling the light insertion layer to the first surface of the light guide layer forming an array of optical apertures optically interconnecting the light insertion layer and the light guide layer. The positioning being such that, when the optical exits of the light insertion layer are deformed, an array of optical apertures optically interconnecting the light insertion layer and the light guide layer is formed. (2) And, deforming at least a portion of the optical exits of the light insertion layer thereby forming the array of optical apertures optically interconnecting the light insertion layer and the light guide layer.
Embodiments of the present invention each have at least one of the above-mentioned object and/or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present invention that have resulted from attempting to attain the above-mentioned object may not satisfy this object and/or may satisfy other objects not specifically recited herein.
Additional and/or alternative features, aspects, and advantages of embodiments of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims.